1. Field of the Invention
The present invention relates to a utility vehicle including a vehicle body frame, a seat frame fastened to the vehicle body frame, a seat bottom fastened to the seat frame and a seat backrest fastened to the seat frame.
2. Description of the Related Art
Japanese Laid-Open Patent Application Publication No. 2007-276703 discloses an example of a conventional utility vehicle. In the utility vehicle, an engine is mounted to a vehicle body frame and a plurality of pipe members are arranged to cover the engine. A seat on which a passenger is seated is fastened to a part of the pipe members. In this utility vehicle, the seat includes a seat frame, a seat bottom and a seat backrest which are unitarily coupled to each other. Therefore, the entire seat is required to be changed even when only a specification of the seat frame is changed depending on a location of the seat, etc. This increases the kinds of the seats and inventory management of the seat is burdensome. When the seat is assembled, it is necessary to incorporate the seat frame into an interior of the seat bottom and the seat backrest, which makes it difficult to assemble the seat.
Japanese Patent Publication No. 3340205 (FIGS. 5 and 6) discloses a seat including a seat frame constituted by round pipes having circular cross-sections, a seat bottom, and a seat backrest. Since it is difficult to fabricate the round pipes constituting the seat frame, a yield of the seat is not improved, and a manufacturing cost increases. In addition, an outer surface of the seat frame constituted by the round pipes cannot be made in surface contact with an outer surface of a vehicle body frame at a joint portion at which the seat frame is joined to the vehicle body frame. For this reason, it is difficult to enhance a joint stiffness and a vibration resistance at the joint portion, which is not suitable in the utility vehicle which tends to vibrate significantly. Under the circumstances, there has been a need for a utility vehicle which can achieve an easier assembling process, reduction of a manufacturing cost, and a higher vibration resistance.